Sleep and Circadian Rhythm Disruption in Psychosis

© 2015 John Wiley & Sons, Inc. Sleep is a complex physiological process involving the interaction of multiple neurotransmitter systems and a diverse network of both arousal and sleep-promoting brain nuclei. This chapter focuses primarily on schizophrenia and bipolar disorder. These disorders form part of a broader psychosis spectrum. Sleep and circadian rhythm disruption (SCRD) has been reported in 30-80% of patients with schizophrenia. In bipolar disorder, sleep disturbances have been shown to be triggers for manic episodes, including irregular sleep timing and reduced total sleep time. Further mechanistic evidence for a link between the circadian system and bipolar disorder comes from work on animal models. Another factor that should be considered in this context is that circadian rhythms and sleep are mechanistically different, albeit interacting, processes. A number of potential mechanisms that may account for SCRD in psychosis are summarized and discussed in more detail in the chapter.